Composite pipe



Oct. 21, 1952 J, B, WAGSTAFF 2,614,585

COMPOSITE PIPE FiledJan. 22,l 1948 www Patented Oct. 21, 1952 lCOMP()SITE PIPE James B. Wagstaff, Ridgewood, N. J., assignor to 'V YHydrocarbon Research, Inc., New York, N. Y.,

a corporation of, NeWJersey l Application January 22, 1948, Serial No.3,726 l 3 claims.' (c1. 413s- 64) f This invention relates to apparatusfor introducing a gas, such asoxygen or oxygen-.enriched air, intoa bathof molten metal.

' The introduction vof oxygen or oxygen-enriched airfinto a bathvcfg-'molten metal, for example, 5:

molten iron in an open hearth furnace to `accelerate the rate ofreduction of the carbon content of the molten iron, has received and isreceiving considerable attention by researchy personnel. In order vtoobtain satisfactory results ithas been found necessary to introduce theoxygen beneath the Vsurface of the bath of molten iron where it willcome into intimate contact with the carbon and effect its removal.Obviously the introduction of loxygen through a steel or iron pipe havythe end portion as the latter melts while feeding oxygen through thispipe into the molten bath.;

Such equipment has many disadvantages, among which ,may be mentioned (1)it involves the use of a cumbersome carriage for the long lengths ofpipe, which carriage and lengths of pipe occupy the space near vthe-open l'hearth furnace' and therefore obstruct and otherwise interferewith the movement of the operators in the Ivicinity of the furnace, (2)it entails frequent interruption lof the feed of the oxygen into thevmolten bath necessitated by the placement of new lengths of pipe on tothe carriage and the connection of ysuch pipe withthe source of oxygen,(3) it involves arduous and time-consuming labor for servicing andoperating the carriage which effects feeding of the length of pipe intothe molten `metal bath, and (4) `it necessitates stock piling longlengths of pipe inthe vicinity of the molten metal bath. A

" It is'a'n object of this Vinvention t'o provide apparatus' forintroducing a gas such,` for example,'as oxygen or oxygen-enriched airbelow vthe surface of a bath of molten metal, e. g., abath of molteniron in an open hearth furnace, which apparatus is compact, isk simpleto construct, is efficient in operation, requires little attention bythe operator and may be used for relatively long periods of time, itseffective life usually being `the same or even longer than the lifeofthe refractory lining'for theI furnace.

VNOther objects and advantages of this invention i 2 f will be apparentfrom the following detailed de scription thereof. f l c j In accordancewith this invention a conduit desirably in the form of a cylindricalpipe extends throughv a wall of an open hearth furnace and has its freeend disposed beneath the surface `ofthe bath of molten metal. The end oftheconduit disposed exteriorly of the vfurnace communicates with asource ofoxygen or other' gas. AV highA temperature, heat-resistantrefractory material completely covers' the portion of the pipe disposedwithin the bath of molten metal extending beyond the end of thepipe-.disposed Within .the bath of molten metal and desirably asubstantial distance above the level of the-bath of molten metal. Thisrefractory covering preferablyconsists of a plurality lof like sectionseachextending along the length of theconduit with the endof onesection'abutting against the adjacentend of a contiguous section, the.abuttingk endsbeing complemental and shaped toprovide a'joint having asubstantial portion thereof disposedatan angle to a plane normal tothellongitudinal axis of the conduit. -In'this-way. relatively shortsections of refractory-material may be shaped and assembled vto providea refractory cover in :which ythel joints between sections'ar`e sodisposed that they do `not permit the molten metal to attack vthemetal'.conduit-through.which the gas flows.

as will be explained more fully hereinafter.

In the preferredfembodiment illustrated on the drawing theinvention'fisl shown incorporated in an oxygen 'feeding device for an.open-hearth furnace and the description which followsWilL-be conned tothe*fpresentil1ustrated `embodiment `of the invention. f Itwillbeunderstood, however,

vscope of this invention is not .connedvfto'the embodiment hereindescribed. n

In the accompanyingdrawing forming apart of this specification andshowing for. purposes of exempliflcation` a preferred form of thisinvention without limiting the claimed inventionto such illustrativeinstance,

Figure 1 is a fragmentary verticali section through an open hearthfurnace embodying my invention; 1

Figure 2l is a fragmentary verticalvsection through the lower portion oftheoxygenfeeding device of Figure 1 showingjone form offhigliteinof thebody portionl9.

`stantial portion thereof extending'in a plane V, tory covering; and

AFigure 4 is a fragmentary vertical section corresponding to Figure 2but showing still another modified form of high temperature,heat-resisting refractory covering.

In the drawing II) indicates an open hearth furnace of well known typehaving a refractory base II on which the bath of molten metal I2 rests,this bath as customary having an upper slag layer I3. The top I4 ofthisfurnace is provided withan opening I5 through which extends theleading end I6 of a metal, desirably steel, conduit I1 which in theembodiment shown in the drawing is a conventional pipe. End I6, as shownin Figure 1, is disposedben'eath the surface of the molten metal bathI2. The end of the conduit I1 positioned exteriorly of the furnace I0 isconnected with a suitable source of oxygen or other gas suppliedthroughthis conduit to the bath of molten metal beneath the surfacethereof.

shown in Figure 2, pipe I1 is protected byv a. high temperature,heat-resistant refractory cover I8. The refractory cover I8 may be 'madeof any suitable material resistant to the temperatures to which the pipeI1 may be subjected; for example, well known re brick, chromerefractory, fused alumina, dolomite, magnesite or silica may be used.

The refractory cover I8 of Figure 2 consists of .a'plurality of sectionseach havinga bore run- 42117112 exterior walls of the pipe andthe wallsof .'thisbore. Each section comprises a cylindrical -body portion I Shaving a cylindrical extension 26 projecting from one end thereof, whichcylindrical extension is of smaller diameter than that At the other enda cylindrical recess *2i is formed having a diameter substantially thesame as that of the extension 20. The sections it will be noted are allalike and are assembled on the pipe l1 so that the lowermost 'section 22is'positioned at the end of the pipe with the walls 23 defining recess2i projecting beyond the end I6 of pipe I1. End I6 is formed integrallyas a flange 24 the outside diameter of which is substantially the sameas the 'diameter of recess 2l so that this flange rfits within 'thisrecess.

Projection 28 of lowermost section 22 snugly fits 'within the recess 2lof the section immediately thereabove. In the same manner the proactionzo of eachl section snugly fits within the recess of a ksectionvimmediately thereabove, the resulting assembly of sections resting onthe Vflange 24` at the end I6 of the pipe I1. There is thus providedarefractory covering in which the joints between lcontiguous Asectionshave a sub;

a an angle to a plane normal to the pipe I1. In the embodiment of theinvention shown in F1gure 2 the joint between contiguous sections is ofstepped configuration and consists of two horizontal portions 25 and 26connected by a vertical portion 21, which vertical portion extends atright angles to a plane normal to the longitudinai axis of pipe n. Theresultant joint construction minimizes entry of molten metal through thejoints between sections into contact with the metal pipe I1, sinceportion 21 of the joint functions as a barrier to the flow of moltenmetal towards the pipe walls.

The abutting walls of projection 20 and recess 2| are ground orotherwise formed to provide smooth contacting surfaces; no cement orother bonding material which would be attacked by the molten metal andprovide a clearance between contiguous sections is employed.

The modification of Figure 3 differs from that of Figure 2 chiefly inthat the refractory covering consists of a plurality of like sections 28each having a bore running the full length thereof of a diameter toreceive pipe I1. Each section comprises a, cylindrical body portion 29,a projecting portion 30 at one end and a complemental recess 3i 'at theopposite end. The projecting portion 30 consists of a truncated conicalsegment 32 and acontiguous cylindrical'segment 33. Recess 3 I consistsof a cylindrical segment 34 and a truncated conical segment, 35. End .I6of the pipe is provided with a collar 36 in the form of a threadedflange fitting within segment 34 of recess 3I. The assembly of sections-28 forming the refractory cover rests on collar 36.

In the construction of Figure 3 each joint between contiguous sectionsconsists of a horizontal portion 31, a conical portion 38 forming themajor portion of the joint, a vertical portion 39 and a horizontalportion 40. The contacting surfaces forming the joint are shapedto-provide intimate contact between the complemental portions ofcontiguous sections and are free of cement or other bonding material. Ajoint thus results in which portions 38 andv 39 are at an angle to aplane normal to the longitudinal axis of pipe I1 portions `38 and 39 actas a barrier preventing contact of molten metal with the walls of pipeI1.

Itwill'be noted conical segment 35 of recess 3l projects beyondcollar 36at the end I6 of pipe I1. The segment 35 provides a protective covering.for the end I6 of pipe I1 and for-collar 36 as will be explained morefully hereinafter.'

In the modification of "Figure 4 the refractory covering -consists of aplurality of sections `each comprising a cylindrical body Yportion 4 IAt one end of the body portion a projection 42 is formed consisting of atruncated conical portion 43 merging into a cylindrical portion 44. Atthe other end a lrecess 45 is formed complemental in shape to projection42, the recess 45 consistingV of va cylindrical segment 46 and atruncated conical segment 41. End I6 of the pipe has welded thereto acollar 48 snugly fitting within the segment 46 of recess v45 in thelowermost section. 'Ihe assembly of sections rests on collar 48. Exceptas here noted, the construction of Figure 4 is the same as thathereinabove described in connection with Figure 3.

In Figures 2, 3 and 4 of the drawing while `the refractory covering hasbeen shown consisting of three sections it will be understood anydesired-number of sections may be used. Furthermore, other shapes ofindividual sections than those shown in the drawings maybe employed aslong as the shapes when assembled in abutting relationship providejoints which have aA substantial portion thereof disposed in a plane atan angle .to a plane normal to the conduit through which the gas issupplied, which joints are close fitting so that at least a portion ofthe joint acts as a barrier preventing penetration of the molten ydrawing, the invention comprehends pipe of other metaltherethrough intocontact with the walls of the conduit I'I. n

In operation the refractory covered conduit or pipe is introduced intothe furnace and before the end I6 is brought into contact with the bathof molten metal the supply of oxygen is turned on. The conduit is thenlowered so that it is immersed into the bathof molten metal, forexample, into the position shown in Figure 1. The existing oxygenprevents the molten metal from coming into contact with the end I6 ofthe metal pipe or with flange 24 of Figure 2, or collars `36 and 48 ofFigures 3 and 4, the portions of the lowermost section of the refractorycover projecting beyond the flange and collars shielding same and theoxygen exiting from these projecting portions under suiiicient pressureto prevent the molten metal from flowing into contact therewith. Theexothermic reaction of the oxygen with the contents of the metal bathtakes place in the locality of the end of the lowermost refractorysection which, it will be noted, is spaced from the end I6 of pipe I1and from the flange 24 or collars 36 and 48. The extending recessed endof the refractory covering therefore protects the end of the pipe, theflange 24 and the collars 36 and 48.

It will be noted this invention provides an improved construction forfeeding a gas beneath the lsurface of a bath of molten metal, whichconshapes. Accordingly, the terms pipe and "conduit are used in theclaims in a broad sense to include pipe or conduit of any desired crosssectional configuration.

What is claimed is:

l. Apparatus for feeding gas into a `bath of molten metal beneath thesurface thereof, coinprising a metal conduit through which the gasflows' and discharges from the free end thereof into the molten metal, ahigh-temperature, heatresistant refractory covering protecting theportion of said conduit in the vicinity of said free end, said coveringconsisting of a plurality of identical sections positioned in abuttingrelationship on said conduit, each of said sections having a borerunning the full length thereof through which said conduit passes, eachsection having at one end thereof a projecting portion of reducedcross-sectional area as compared with the cross-sectional area of thebody rportion of said section and a recess complemental in shape to theprojecting portion at the other end thereof,

the length of said projecting portion and of said recess being at leastabout as great as the thickness of said body portion of said section,the recess of the terminal section disposed at said free end extendingbeyond said free end and the projecting portion of said terminal sectionbeing struction is compact, simple in design, efficient and durable inoperation. Since the refractory coveri's made from refractory shapes allof which are the same, it is relatively inexpensive to assemble andmaintain. Should any of the sections of the refractory covering for anyreason become defective, it is not necessary to replace the entirecovering but only such defective section.

The protective cover` for the metal pipe may be f of the ysamerefractory material as the base Il. Since the refractory -cover does notsupport the Weight of the molten metal bath, in general, it will outlastthe base I I.

It is well to observe that the through the sections of the refractorycovering be of a little larger size than the overall size of the pipewhich is to pass therethrough so as to avoid cracking orinjury of therefractory covering because ofthe greater thermal expansion of the pipewhen the pipe with the covering theron is introduced into the hotfurnace. Even though the refractory covering does not fit snugly aroundthe pipe, molten metal is kept from iiowing up into the clearancebetween the covering and the pipe by the pressurized gas dischargingfrom the end of the pipe which is immersed into the molten Vmetal bath.

Since diiferent embodiments of the invention can be made withoutdeparting from the scope of this invention, it is intended that allmatter contained inl the above description or shown in the accompanyingdrawing shall be interpreted as illustrative and not in a limitingsense. Thus while a cylindrical pipe has been shown in the bore runningpositioned within the recess' of the contiguous abutting section, andmeans on said free end for maintaining the sections of said covering onsaid conduit, said means being of a configuration that nts well Within-said recess of said terminal seco tion.

' 2. Apparatus as dened in claim 1 wherein thel metal conduit iscylindrical, each section of said covering is cylindrical, theprojecting portion of each section comprises a cylindrical part, and themeans for maintaining the sections of said covering on said conduit is aflange on the free end of said conduit.

3. Apparatus as dened in claim l wherein the metal conduit iscylindrical, each section of said covering is cylindrical, theprojecting portion of each section comprises a frusto-'conical part, andthe means for maintaining the sections of said covering on said conduitis a flange on the free end of said conduit. c

JAMES B. WAGS'IIAFF.

REFERENCES CITED The following references are-of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 905,948 Stromborg Dec. 8, v19081,330,310 Du Mazuel Feb. 10, 1920 1,949,731 Soldatoif Mar. 5, 1934FOREIGN PATENTS Number Country l Date 82,103 Sweden Nov. 27, 1934

